Customer: Société Tunisienne des Industries de Raffinage (STIR)
Task: Energy Audit
End User: STIR Refinery
Location: Bizerte (Tunisia)
Period: 2009- 2011
A study was carried out jointly with TECI (Tunisian Engineering Company) to analyse actions aimed at energy conservation and production improvement of process units, power stations, product handlings, utilities and electrical devices.
Within the study, the consortium Prometheus-TECI has globally studied 33 actions and has deepened the valuable ones as follows:
- Evaluation of process modifications involved
- Investment assessment
- Analysis of economic returns (project pay-out)
In this context, Prometheus has realised the following optimisation/design studies: CDU (12 actions), Reforming Unit (5 actions); Auxiliary Units (5 actions); Power Station (4 actions); Logistics and Tank Farms (4 actions).
Prometheus delivered a process revamping study covering almost all refinery sections to improve yields, energy efficiency, and environmental impact in practice.
The main points faced within the CDU study are:
- Insertion of Crude Flash Drum and splitting of preheat train in two sections.
- Pinch Revamp of preheat train reaching an approach temperature of 40°C (previously 69°C) and a Furnace Inlet Temperature of 293°C.
- Re-design of Main Fractionator, Side Strippers and Naphtha Splitter (with side cut for benzene).
- Reboiled side strippers to avoid water in distillates.
- Furnace condition checks after light ends removal.
- Furnace air preheat with exhausted steam.
- Stabiliser debottlenecking.
- Exchangers mechanical check at new conditions.
- New items specifications (pumps, drums, columns, exchangers, instrumentation).
- Cost evaluation.
